add v9 annex.version, not yet the default

This is the start of v9, but it's currently identical to v8, and v8 is
not upgraded to it. git-annex upgrade will upgrade to v9 with this
change.

Sponsored-by: Dartmouth College's Datalad project

Annex/Version.hs

@@ -1,6 +1,6 @@
 {- git-annex repository versioning
  -
- - Copyright 2010-2019 Joey Hess <id@joeyh.name>
+ - Copyright 2010-2021 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -22,16 +22,16 @@ defaultVersion :: RepoVersion
 defaultVersion = RepoVersion 8
 
 latestVersion :: RepoVersion
-latestVersion = RepoVersion 8
+latestVersion = RepoVersion 9
 
 supportedVersions :: [RepoVersion]
-supportedVersions = map RepoVersion [8]
+supportedVersions = map RepoVersion [8, 9]
 
 upgradableVersions :: [RepoVersion]
 #ifndef mingw32_HOST_OS
-upgradableVersions = map RepoVersion [0..7]
+upgradableVersions = map RepoVersion [0..8]
 #else
-upgradableVersions = map RepoVersion [2..7]
+upgradableVersions = map RepoVersion [2..8]
 #endif
 
 autoUpgradeableVersions :: M.Map RepoVersion RepoVersion

Upgrade.hs

@@ -26,6 +26,7 @@ import qualified Upgrade.V4
 import qualified Upgrade.V5
 import qualified Upgrade.V6
 import qualified Upgrade.V7
+import qualified Upgrade.V8
 
 import qualified Data.Map as M
 
@@ -96,6 +97,7 @@ upgrade automatic destversion = do
 	up (RepoVersion 5) = Upgrade.V5.upgrade automatic
 	up (RepoVersion 6) = Upgrade.V6.upgrade automatic
 	up (RepoVersion 7) = Upgrade.V7.upgrade automatic
+	up (RepoVersion 8) = Upgrade.V8.upgrade automatic
 	up _ = return True
 
 	-- Upgrade local remotes by running git-annex upgrade in them.

Upgrade/V8.hs

@@ -0,0 +1,17 @@
+{- git-annex v8 -> v9 upgrade support
+ -
+ - Copyright 2022 Joey Hess <id@joeyh.name>
+ -
+ - Licensed under the GNU AGPL version 3 or higher.
+ -}
+
+module Upgrade.V8 where
+
+import Annex.Common
+
+upgrade :: Bool -> Annex Bool
+upgrade automatic = do
+	unless automatic $
+		showAction "v8 to v9"
+
+	return True

git-annex.cabal

@@ -1069,6 +1069,7 @@ Executable git-annex
     Upgrade.V5.Direct
     Upgrade.V6
     Upgrade.V7
+    Upgrade.V8
     Utility.Aeson
     Utility.Android
     Utility.Applicative